PORTSMOUTH - Families and photographers gathered on the banks of the Piscataqua River in the wee hours of Monday morning to watch the final float-in for the Memorial Bridge project.

Around 1:15 a.m. the center span of the lift bridge was floated downriver from the New Hampshire State Pier aboard the barge Cape Cod and guided by several tugboats. The span was floated through the north and south fixed spans of the bridge and spun around just downriver of the bridge. Over the course of the morning, it will be guided into place with about five to six inches of clearance on each side. It will be placed atop two temporary pedestals before the barge is removed.

The river channel will be closed through 1 a.m. on June 22 as the counterweight cables are connected to the span and tested.

It is the last major milestone for the bridge before it opens in July.

"It's exciting because it is one step closer to getting the project completed," said Denis Switzer, contract administrator with the New Hampshire Department of Transportation. "We are within striking distance."

He said he would have expected more people to turn out for the float-in. Crowds were small compared to some of the other major milestones associated with the highly visible project, including the float-out of the old center span on a bitterly cold February morning in 2012.

"I'm personally disappointed because it has been such a community event, there has been so much interest and so many people here, it feels like they just come out of the woodwork," Switzer said.

He referred to the float-in as the "second most dramatic" event that will take place in the construction of the new bridge.

"The first will be when we open it to traffic," he said.

Many of those who did turn out said they came to watch history happen.

"It is just a historic thing. We'll never see it again," Henry Whitney of South Berwick, Maine, said from the Portsmouth side where he watched the event with his brother, Stan, of Portsmouth. Their brother, George, was watching from the Kittery side.

Henry Whitney said seeing the center span in place will give people confidence that the project is really going to be done on schedule.

Amanda Buckley of Eliot, Maine, watched the float-in from the deck at One Harbour Place with her two children, Nevaeh, 4, and Jackson, 6.

"They were just really excited about the bridge. We live in Eliot and we love coming on this bridge when it is nice out to go to all the downtown places," Buckley said.

Wayne and Carolyn Gardner traveled from York, Maine, to witness the event.

"I find it amazing the detail to their work. The team really needs to be proud of the work they've done and the time they've done it in," Carolyn Gardner said.